Chemical Reactions MS-PS1-5

Grade 7 - NGSS - CA

The smallest particle of an element

Atom

The smallest particle of an element. Atom. An atom is the basic building block of all matter, like tiny pieces that make up everything around us.

A number placed in front of a symbol or formula in a chemical equation

Coefficient

A number placed in front of a symbol or formula in a chemical equation. Coefficient. In chemistry, a coefficient tells you how many molecules or atoms of each substance are involved in a reaction.

States that mass cannot be created or destroyed in a chemical reaction

Law of conservation of mass

States that mass cannot be created or destroyed in a chemical reaction. Law of Conservation of Mass. In a chemical reaction, the amount of stuff you start with is the same as the amount you end with, just rearranged.

A representation of an object or system

Model

A representation of an object or system. Model. In Grade 7 NGSS, a model is a simplified way to show how something works or looks by using drawings, diagrams, or simulations.

A group of atoms held together by bonds

Molecule

A group of atoms held together by bonds. Molecule. A molecule is like a tiny building block made of atoms that join together, forming everything around us.

A new substance formed by a chemical reaction

Product

A new substance formed by a chemical reaction product. In a chemical reaction, a product is the new substance that is created when the original substances, called reactants, interact.

A substance that is changed in a chemical reaction

Reactant

A substance that is changed in a chemical reaction. Reactant. In simple terms, a reactant is a starting material in a chemical reaction that gets used up as it turns into products.